The present invention concerns a contact arrangement for electric power switches.
Medium voltage switch panels can be equipped with built-in switch units or with removable switch units, which switch units are usually power switches. Such a power switch is typically mounted on a carriage type switch unit and can be electrically connected, by break contacts, with the switch panel when the carriage type switch unit is pushed into the switch panel. It is important that the moveable contacts of the carriage type switch unit be able to interlock properly with the opposed contacts which are fixedly arranged at the switch panel.
The published German Patent Application No. 1,665,986 describes a contact arrangement, for a removable switch unit in a switch panel, which has a knife blade contact member and a retaining device member, said retaining device member being movable relative to the knife blade contact member. Due to the limited lateral travel of the contact sections of the contact arrangement placed in pairs opposite to each other, it becomes necessary to lead the interlocking contacts toward each other with great accuracy so that they will engage properly. The carriage type switch carrying the contact members must therefore be moved into the switch panel in a precise manner, making it necessary to use close tolerances at greater manufacturing cost.
Accordingly, it is a primary object of this invention to provide a contact arrangement with one contact member, preferably a male knife blade contact member and at least one other contact member, preferably a female member movable relative to the one member so that the two will securely interlock even with a coarsely centered alignment.
The invention solves the above-mentioned object and others in that the female contact sections are held, self-supported towards the open contact side, and are self-centering relative to the male knife blade contact member. The female contact sections are arranged between the end portions of a U-shaped support. The contact sections and the U-shaped support are connected at one of their ends with the contact support by two bolts which pass through the contact support and are arranged perpendicularly thereto. In an area bounded by the two bolts, the U-shaped support, and the contact support there is provided a spring arrangement for self-centering the female contact sections relative to the male knife blade contact.
The spring arrangement can comprise two trapezoidally-shaped leaf springs united at their narrow base sides, the leaf springs extending vertically to the contact support. The free, inwardly bent, ends of the leaf spring's legs will rest at the bolts on one side and at the U-shaped support and the contact support on the other side.
The invention is also advantageous in that if the switch gear is placed on its side greater lateral tolerances for the axial alignment of the male knife blade contact with the female contact will be acceptable. Also, height related tolerances pose no problem due to the knife blade design of the contact. The proposed contact arrangement is particularly suited for switch panels which have removable switch gear.